A tiny island off the Western Australia coast continues to throw light on a four century old tale of a shipwreck and mass murdersReuters

A grave unearthed on a tiny island off Western Australia's coast throws new light on the mass murders that followed the Batavia shipwreck four centuries ago.

The 11th skeleton found on Beacon Island since the 60s belongs to an adolescent. Two musket balls were found near the body.

"This is the first human burial to be found undisturbed through archaeological investigations, and represents a unique opportunity to reconstruct events surrounding this individual's death and internment," said Dr Daniel Franklin from The UWA Centre for Forensic Science.

The details are expected to throw light on the life and times of the sailors, besides revealing how they met their death.

More than half the survivors are believed to have died in a mutiny that followed.

The Dutch East India vessel Batavia was on its maiden voyage carrying gold and silver to obtain spice in return. When it wrecked on Morning Reef in 1629, it had over 300 people on board, including women and children.

While 40 drowned, the survivors managed to swim to the nearby Beacon Island.

What then followed is a horrific tale of treachery and murder as the survivors fought over the available stock of food.

"Many individuals died, it was a horrendous event, and yet we know many of those people died in the water. Presumably they were disposed of in surface conditions, so we wouldn't expect at all for many of [their remains] to survive ... but we're finding them, so some of them do," said UWA archaeologist professor Alistair Paterson.

It is believed that even as the captain went with a small group to Java seeking help, the undermerchant who assumed charge of the group, began a calculated mission of murder and rapes.

A mass grave was discovered on Beacon Island in 1999, but archaeologists had to wait for 15 years before old fishermen shacks on the spot were removed to comb for clues.

The WA Museum's head of maritime archaeology, Jeremy Green, said the find was a major step in better understanding what was an internationally significant chapter in history.